Add tests for the svnauthz command.

Doing this also meant rather than symlinking svnauthz-validate to svnauthz,
just making another target for the svnauthz.c file.  Reasoning for this is that
libtool does not get along well with passing a different argv[0] in than what
the file is named.

To allow it to work on platforms where the lt-svnauthz file is created strip
lt- from the start of the command name before determining if we should run 
in compat mode.

* Makefile.in
  (INSTALL_EXTRA_TOOLS): No longer need to symlink svnauthz-validate.

* build.conf
  (__ALL__): Add svnauthz-validate target to win32 build.
  (svnauthz-validate): New target.

* subversion/tests/cmdline/svnauthz_tests.py: New file.

* subversion/tests/cmdline/svntest/actions.py
  (run_and_verify_svnauthz): New function.

* subversion/tests/cmdline/svntest/main.py
  (svnauthz_binary, svnauthz_validate_binary): New variables to hold
    the path to the svnauthz and svnauthz-validate commands.
  (run_svnauthz, run_svnauthz_validate): New wrappers to run_command for 
    svnauthz and svnauthz-validate.
  (create_parser): New option to tests to specify the path to find tools.
  (execute_tests): Handling overriding svnauthz*_binary vars based on
    the --tools-bin option.

* tools/server-side/svnauthz.c
  (SVNAUTHZ_LT_PREFIX): New define.
  (use_compat_mode): Skip over "lt-" prefix on command name when deciding if
    we should run in compatability mode.


git-svn-id: https://svn.apache.org/repos/asf/subversion/trunk@1438206 13f79535-47bb-0310-9956-ffa450edef68